What Happened???

**asm481** · September 11th, 2002, 05:03 PM

A few days ago a friend brought me his computer saying he had messed up and got the love letter virus (didn't update his antivirus of course!) and then he says all of a sudden i don't get anything on the screen when I power it up. So I am gonna try and help him out and first take the drive and slave it to one of mine and sure enough it is loaded with the vbs virus. I format that drive as there is nothing important on it and attack his other problem. The computer on start up gives no beeps and nothing on the screen however you can just hear the HDD spinning up and the keyboard flashes as if it is trying to start but still no video. So I think there may be a problem with the AGP port and put in a PCI video card---still dead... All parts check out ok in my other 'puter. I put in a new motherboard (ECS K7S5A) and get it all set up and running fine as of last night. Loaded O/S programs run for a while no problems. Today I get home from work and power it up and again, no video, the two cd drives are flashing and it shows HDD activity but zero video. It will not act any different with a boot disk, and I tried resetting CMOS to default to no avail. What is going on here? And sorry if this in wrong forum but doesn't seem to fit anywhere else!

**Archer** · September 11th, 2002, 05:07 PM

just a suggestion but try a new power supply

**asm481** · September 11th, 2002, 05:34 PM

Ok, I replaced with another power supply and still no change or did I already toast the MB?

**NooNoo** · September 11th, 2002, 05:36 PM

What was the old powersupply and what about the new one?

Does the cpu show any signs of being cracked chipped or burned?

Are you sure the hsf is up to the job?

**Archer** · September 11th, 2002, 05:37 PM

Looks like your back to retesting all the parts in another system as the old power supply may have had detrimental efects to the motherboard.

**asm481** · September 11th, 2002, 06:05 PM

Noo-Noo, the CPU looked fine when I did the swap, and the system was up and running for hours yesterday without excess heat showing; according to BIOS. The power supply was a Sparkle Power unit 250 watt. I just threw an old 200 watt "U Power" power supply I had here and get the same blank screen.

**Garak** · September 11th, 2002, 06:52 PM

OK, this sounds abit fishy, a 250watt PSU generally isnt enough to run an AMD chip (well atleast..)

Possible BIOS chip corruption by another virus (Win95 virus pops to mind) - I would personally fdisk /mbr the suspect drive, or fully fdisk it.

Now for the board problem, do you have 300watt PSU you can test the board on?

If you check my bookmark's you will find some helpfull topics by Ruslan incase it is a BIOS IC problem.

Do the fans spin, drives spin up??

Good Luck.

**Quiet Thunder** · September 11th, 2002, 07:26 PM

Take out all the cards, and unhook and cdroms ect...

Take everything out, including the processor. Then put the processer, heatsink, fan, video card, memory, and floppy drives back in. NOTHING else. Can you boot? If not, use a multimeter to test current from the powersupply. If all still dosn't work, and you KNOW the memory, psu, and vid card are all working, then you got a bad mobo or bad bios.

Edit: The reason I asked you to take everything out, is because I've found that occasionally a simple reseat of the processor or vid card or even memory helped.

Odd side note: I recently had a odd occurance. I was handed one of those "Find out why it won't work" computers. Computer was a pent 200 or something. Horribly old. Ended up being the CD-Rom that was causing the problems. I've never herd of a CD-Rom prevent a computer from getting to post, but stranger things have happened. Basically the moral of the story, NEVER overlook anything. Which reminds me. Don't forget to check the power cable.

**DocPC** · September 11th, 2002, 07:32 PM

Had the same (kinda) issue with a loveletter virus last week. Put a different AGP card in and it worked. This was AFTER the virus removed.

??????

**Garak** · September 11th, 2002, 08:00 PM

maybe a new strain of the virus???

Never come across that Doc - most definatly weird!!!

**DocPC** · September 11th, 2002, 08:30 PM

Dunno Gary.............Just know it worked. I didn't get to remove it as the customer was savvy enough to know what he had.....

**Ruslan** · September 11th, 2002, 10:01 PM

Sounds like dead motherboard to me...

**asm481** · September 12th, 2002, 09:34 PM

OK so I killed the second board in this PC and I strongly suspect the power supply as the cause. How do I test the power supply without burning out more motherboards. I know there is a special tester made for it but I don't have one of these gems....just a voltmeter.

**Ruslan** · September 12th, 2002, 10:54 PM

Originally posted by asm481
OK so I killed the second board in this PC and I strongly suspect the power supply as the cause. How do I test the power supply without burning out more motherboards. I know there is a special tester made for it but I don't have one of these gems....just a voltmeter.

Oopss...

Check the PSU without load - You should check the +5VSB (standby module) voltage - quite often exactly that module kills motherboards.

Short "power-ON" pin on the PSU with case or with any of black wires - PSU will start. (which exactly pin - refer to motherboard's manual... or sometimes it can be listed on the PSU's cover...)
Usually it is green color wire, but some of PSU manufacturer's could use another color for that wire... Have seen it also...

Actual load for testing PSUs can be few powerful enough resistors (15 - 50W), connected to different output channels (+5V,+12V,+3,3V), and few LEDs with less powerful resistors, connected to the rest of channels. I've built that tester by myself,by the way, and it worked...

If all O'K with +5VSB module, You can use any (even failed motherboard) as load (even without CPU)... check all the voltages using voltmeter...

**AberTechGav** · September 13th, 2002, 07:46 AM

Hi all..

Here's an idea that solved a three-week problem.

Motherboard was dead - no boot, but hdd and cdroms all initialised.
I traied everything - replaced PSU, memory, processor, etc... but nothing worked.

I stripped the mobo off the backlplate last night, and fired it up OUT of the case. Damn thing worked. Turns out the case had been fitted with an extra support for the mobo, which was shorting between the memory components. When the owner when in the case to have a mooch around, he re-seated the memory and pushed the support into the mobo rear.

Gave the symptom of a continual reset, or a dead mobo.

Just an idea...pretty unlikely, but you never know...

Gav

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